PARIS-A controversial biographical film on Princess Grace of Monaco, which has been slammed by the former Hollywood star’s children as “pure fiction”, will open the Cannes film festival, the organisers said Friday. The world preview of “Grace of Monaco” will take place on May 14 in the out of competition category, a statement said. It will simultaneously be released in France and several cities around the world. The 67th Cannes film festival will run from May 14-25 in the southern France resort town.  The film, directed by France’s Olivier Dahan and featuring Australian actress Nicole Kidman as Grace Kelly, the Hollywood star-turned-princess.